<template>
  <div class="list" ref="wrapper">
    <div>
      <div class="area">
        <div class="title border-topbottom">当前城市</div>
        <div class="button-list">
          <div class="button-wrapper">
            <div class="button">{{city}}</div>
          </div>
        </div>
      </div>
      <div class="area">
        <div class="title border-topbottom">热门城市</div>
        <div class="button-list">
          <div class="button-wrapper" 
          v-for="item of hot" 
          :key="item.id"
          @click="handleChangeCity(item.name)"
          >
            <div class="button">{{item.name}}</div>
          </div>
        </div>
      </div>
      <div class="area" v-for="(item,key) of cities" :key="key"
      :ref="key">
        <div class="title border-topbottom">{{key}}</div>
        <div class="item-list">
          <div class="item border-bottom" 
          v-for="innerItem of item" 
          :key="innerItem.id"
          @click="handleChangeCity(innerItem.name)"
          >
          {{innerItem.name}}
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import Bscroll from 'better-scroll';
import {mapState} from 'vuex';
export default {
  name: "CityList",
  props:{
    hot:Array,
    cities:Object,
    letter:String,
  },
  // 当页面加载完毕创建一个wrapper组件DOM的Bscroll实例
  mounted(){
      this.scroll=new Bscroll(this.$refs.wrapper,{click:true})
  },
  // 将state中的city属性映射到computed中的city属性上
  computed:{
    ...mapState(['city'])
  },
  // 当item组件被点击后，执行store中的mutations中的change方法；
  // 跳转到首页
  methods:{
    handleChangeCity(city){
      this.$store.commit('change',city);
      this.$router.push('/')
    }
  },
  // 设置侦听器，当this.letter发生改变时，执行letter()函数;
  // 设置element为this.letter代表的字母的组件的DOM；
  // 执行this.scroll.scrollToElement方法，滚动到element的DOM的所在位置
  watch:{
    letter(){
      if(this.letter){
        const element=this.$refs[this.letter][0]
        this.scroll.scrollToElement(element)
      }
    }
  }
};
</script>

<style lang="scss" scoped>
@import "~@/assets/style/varibles.scss";
.border-topbottom {
  &:before,
  &:after {
    border-color: #ccc;
  }
}
.border-bottom {
  &:before {
    border-color: #ccc;
  }
}
.list {
  position: absolute;
  top: 1.58rem;
  left: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;
}
.title {
  line-height: 0.54rem;
  background-color: #eee;
  padding-left: 0.2rem;
  color: #666;
  font-size: 0.26rem;
}
.button-list {
  padding: 0.1rem 0.6rem 0.1rem 0.1rem;
  overflow: hidden;
  .button-wrapper {
    width: 33.33%;
    float: left;
    .button {
      text-align: center;
      margin: 0.1rem;
      border: 0.02rem solid #ccc;
      padding: 0.1rem 0;
      border-radius: 0.06rem;
    }
  }
}
.item-list {
  .item {
    line-height: 0.76rem;
    padding-left: 0.2rem;
  }
}
</style>